Such a device, and especially a roller skate with pairs of front and rear wheels journaled on respective transverse axles, is conventionally provided with a front bumper or stop of plastic material designed to facilitate push-off, figure skating and similar maneuvers. These stops, however, are generally not usable for braking at high speeds since, on the one hand, such action would result in rapid wear of the bumper and, on the other hand, the location of the stop at the forward end of the device may potentially give rise to accidents due to a flipping about the front-wheel axle.
In light of the high speeds attainable with today's efficiently constructed roller skates and skate boards, however, it is desirable to provide these devices with means for enabling a controlled deceleration or stopping whenever a need therefor should arise.